There will be no Armageddon

A black hole will appear in mid-July on the border between France and Switzerland, swallowing up first Europe and then the entire planet. Such are the apocalyptic forecasts being made ahead of the scheduled launching, in three weeks, of the Large Hadron Collider (LHC).

The ambitious research project, aimed at looking into superconductivity, high energies and God or devil knows what else, is an international effort involving several countries, including Russia. The report that the LHC will also produce a black hole is the most talked about item.

Remarkably, the most powerful sources of radiation in the universe are not those driven by thermonuclear reactions or annihilation processes. Much more powerful are high-density objects called black holes and neutron stars. The force of gravity around these bodies is tremendous, and accelerates any matter caught by its pull to immense speeds. Matter impacting on the surface of a neutron star does so at half the speed of light. The efficiency at which energy is released from such impacts is more than ten times that of nuclear or thermonuclear reactions.

The general theory of relativity says black holes appear when matter is compressed into a more compact shape than that of a neutron star. As a result, a black hole has a gravitational field so strong that neither a material body nor any kind of radiation (including light) is able to escape its embrace. The black holes are, therefore, impossible to see. They can only be identified indirectly, by observing the matter they absorb from a neighboring visible star, for example.

The gas flowing from such a star does not fall into the black hole at once. First, it forms the so-called “accretion disk”, where the matter rotates for a long time. As it accelerates, it picks up a speed approaching that of light and starts emitting super-high energy X-radiation, which can be measured by instruments placed in space.

Will it be possible to reproduce these phenomena, as yet only theoretically predicted, in the ground-based accelerator in the Alps?

The hadron collider straddling the French-Swiss border is a ring accelerator designed to collide charged particles into each other at massive speeds. When it is turned on more than a billion collisions per second will occur inside it. The huge circumference of the collider ring (26.65 km) will allow the LHC to whisk particles to speeds close to that of light and produce super-high energy collisions.

The LHC is expected to generate collision energies of proton bunches (rather than traveling in a continuous beam, particles in accelerators are generally “bunched” together) as high as 7 teraelectronvolts (TeV). Electron-proton bunches will collide with energies of up to 1.5 TeV, and bunches of heavy ions, such as lead, with a total energy of over 1,250 TeV. This is nothing short of a new phenomenon in physics, in particular the likely confirmation of a theory that teraelectronic energies and corresponding gravitation give rise to black holes.

Some theorists, however, and the public at large have started voicing fears that when such processes are modeled there will be a danger of collider experiments getting out of hand and giving rise to a chain reaction that could destroy our planet. The most widely expressed fear is that microscopic black holes may appear and capture the surrounding matter.

Some people take this threat extremely seriously. In March of this year a claim was even filed with the Hawaii district court charging CERN (the European Organization for Nuclear Research), which is building the accelerator, with an attempt at Armageddon, and demanding a ban on the accelerator’s launching.

Meanwhile, several years ago, it was discovered that black holes “evaporate” with time – a crucial discovery for understanding their physics. Larger ones do so only slowly, over billions of years, while smaller ones, practically instantaneously, within 10-17 of a second. Naturally, they simply do not have the time to absorb any sizeable amount of matter.

Some researchers also believe that black holes arise when space rays bombard, at much higher energies, the Earth’s atmosphere, the Moon and the surfaces of other planets. We just cannot see them because the process is too short-lived.

Black holes are expected to appear (or be detected appearing) in the LHC every second or so. As they evaporate they will leave a trail of radiation that will be registered by the accelerator’s monitoring devices. Such holes pose no threat, even in theory. On the other hand, they should help improve our understanding of the relationship between quantum mechanics and gravitation, because evaporation of black holes is a quantum mechanical process.

It is estimated that it will take about 20 million CDs to record the data produced by the collider and 70,000 mainframe computers to process it. But what is important is not the volume of data but the findings physicists can draw from it. The super-accelerator, by throwing light on the evolution of black holes, will also recreate the conditions that obtained in the universe within one-billionth of a second of the Big Bang. That, scientists hope, will help to answer many questions about how our world began, questions usually still discussed on a theoretical plane.

Yury Zaitsev is an analyst at the Institute of Space Research.

The opinions expressed in this article are the author’s and do not necessarily represent those of RIA Novosti.

http://en.rian.ru/analysis/20080618/111107931.html